Heat loss characteristics of typology-based apartment building external walls for a digital twin-based renovation strategy tool

Information about existing building structures is necessary for creating a renovation strategy. Older buildings are often built using typical building envelope structures. However, this information is presented in the building register at a general level, specifying the material type but not its characteristics. For a cross-regional reconstruction strategy, it is necessary to link the scarce information in the building register with the heat loss characteristics of the building envelope structures. In the current study, we classified external wall solutions according to building typologies and linked this with building register information. The typology database includes log, timber frame, brick, concrete, and aerated lightweight concrete external wall structures. Comparing the typology-based values and the actual situation showed that the wall structures’ expected and actual heat loss characteristics agreed. However, there were also significant deviations, primarily because the data from the building register did not allow for precise classification. Nevertheless, data showed that building typology-based heat loss properties are necessary for developing a district-based renovation strategy.